U.S. patent application number 11/609967 was filed with the patent office on 2007-07-12 for spinous process fixation implant.
This patent application is currently assigned to SPINEFRONTIER LLS. Invention is credited to DANIEL R. BAKER, KINGSLEY RICHARD CHIN, DANIEL F. JUSTIN.
Application Number | 20070162001 11/609967 |
Document ID | / |
Family ID | 38163619 |
Filed Date | 2007-07-12 |
United States Patent
Application |
20070162001 |
Kind Code |
A1 |
CHIN; KINGSLEY RICHARD ; et
al. |
July 12, 2007 |
SPINOUS PROCESS FIXATION IMPLANT
Abstract
An implantable spinous processes fixation device including a
first S-shaped plate having a first surface configured to engage a
first lateral surface of a first spinous process and a second
surface configured to engage a second lateral surface of a second
spinous process and a second S-shaped plate having a first surface
configured to engage a second lateral surface of the first spinous
process and a second surface configured to engage a first lateral
surface of the second spinous process. The first and second
S-shaped plates are configured to pivot around an axis
perpendicular to the center portions of the first and second
S-shaped plates.
Inventors: |
CHIN; KINGSLEY RICHARD;
(PHILADELPHIA, PA) ; BAKER; DANIEL R.; (SEATTLE,
WA) ; JUSTIN; DANIEL F.; (LOGAN, UT) |
Correspondence
Address: |
AKC PATENTS
215 GROVE ST.
NEWTON
MA
02466
US
|
Assignee: |
SPINEFRONTIER LLS
PHILADELPHIA
PA
|
Family ID: |
38163619 |
Appl. No.: |
11/609967 |
Filed: |
December 13, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11609418 |
Dec 12, 2006 |
|
|
|
11609967 |
Dec 13, 2006 |
|
|
|
60750520 |
Dec 14, 2005 |
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Current U.S.
Class: |
606/276 |
Current CPC
Class: |
A61B 17/7065 20130101;
A61B 17/7068 20130101 |
Class at
Publication: |
606/061 |
International
Class: |
A61F 2/30 20060101
A61F002/30 |
Claims
1. An implantable assembly for stabilization of spinous processes,
comprising: a first S-shaped plate having a first surface
configured to engage a first lateral surface of a first spinous
process and a second surface configured to engage a second lateral
surface of a second spinous process; a second S-shaped plate having
a first surface configured to engage a second lateral surface of
said first spinous process and a second surface configured to
engage a first lateral surface of said second spinous process;
wherein said first and second S-shaped plates are configured to
pivot around an axis perpendicular to the center portions of said
first and second S-shaped plates.
2. The assembly of claim 1 further comprising a post member
configured to pass through concentrically aligned through-bore
openings formed in said centers of said first and second S-shaped
plates.
3. The assembly of claim 2 wherein said second S-shaped plate
comprises top and bottom components configured to pivot around said
axis independent of each other.
4. The assembly of claim 3 wherein said top and bottom components
are configured to pivot around said post member and to set first
and second pivot angles with said first S-shaped plate,
respectively, thereby defining first and second spaces between said
first S-shaped plate and said top and bottom components,
respectively.
5. The assembly of claim 2 wherein said second S-shaped plate is
configured to pivot around said post member and to set first and
second pivot angles with said first S-shaped plate, respectively,
thereby defining first and second spaces between said first
S-shaped plate and said top and bottom portions, respectively.
6. The assembly of claim 2 wherein said post member comprises a
locking element for securing and preventing pivoting of said first
and second S-shaped plates.
7. The assembly of claim 6 wherein said post member comprises an
elongated bolt and said locking element comprises threads formed at
a portion of said bolt, dimensioned to engage inner threads in said
first S-shaped plate through-bore.
8. The assembly of claim 6 wherein said post member comprises an
elongated bolt and said locking element comprises threads formed at
a portion of said bolt, dimensioned to engage a nut after the bolt
exits said S-shaped plates through-bores.
9. The assembly of claim 1 wherein said first and second surfaces
of said first and second S-shaped plates comprise protrusions
configured to engage and frictionally lock said S-shaped plates
onto said first and second spinous processes.
10. The assembly of claim 9 wherein said protrusions are selected
from a group consisting of teeth, spikes, serrations, rough
coatings and ridges.
11. The assembly of claim 1, wherein said center portions of said
first and second S-shaped plates are dimensioned to fit between
said first and second spinous processes and comprise edges sculpted
to conform to the shape of said spinous processes.
12. The assembly of claim 3, wherein said first and second pivot
angles comprise values between zero and 180 degrees.
13. The assembly of claim 1 wherein said first and second S-shaped
plates are pivoted to a horizontal orientation for sidewise
insertion of said assembly between said first and second spinous
processes.
14. The assembly of claim 1 wherein said assembly is assembled
prior to being implanted between said first and second spinous
processes.
15. The assembly of claim 1 wherein said assembly is assembled
after being implanted between said first and second spinous
processes.
16. The assembly of claim 1 further comprising a top locking member
configured to lock said first and second S-shaped plates' top
ends.
17. The assembly of claim 16 wherein said top locking member
comprises a long bolt configured to be threaded through bolt holes
formed through said first S-shaped plate's top end, said first
spinous process and said second S-shaped plate's top end.
18. The assembly of claim 16 wherein said top locking member is
selected from a group consisting of staples, cables, sutures, pins
and screws.
19. The assembly of claim 1 further comprising a bottom locking
member configured to lock said first and second S-shaped plates'
bottom ends.
20. The assembly of claim 19 wherein said bottom locking member
comprises a long bolt configured to be threaded through bolt holes
formed through said first S-shaped plate's bottom end, said second
spinous process and said second S-shaped plate's bottom end.
21. The assembly of claim 19 wherein said bottom locking member is
selected from a group consisting of staples, cables, sutures, pins
and screws.
22. The assembly of claim 1 wherein said first and second S-shaped
plates comprise material selected from a group consisting of
stainless steel, titanium, gold, silver, alloys thereof, absorbable
material, non-metal materials including synthetic ligament
material, polyethylene, extensible materials and combinations
thereof.
23. The assembly of claim 1 further comprising a center plate
configured to pivot around said axis and being dimensioned to fit
between said first and second spinous processes and comprising
edges sculpted to conform to the shape of said spinous
processes.
24. The assembly of claim 1 wherein said first and second S-plates
comprise adjustable lengths.
25. A method for stabilizing spinous processes of a spinal column,
comprising: providing a first S-shaped plate and engaging a first
surface of said first S-shaped plate with a first lateral surface
of a first spinous process and a second surface of said first
S-shaped plate with a second lateral surface of a second spinous
process; providing a second S-shaped plate and engaging a first
surface of said second S-shaped plate with a second lateral surface
of said first spinous process and a second surface of said second
S-shaped plate with a first lateral surface of said second spinous
process; and wherein said first and second S-shaped plates are
configured to pivot around an axis perpendicular to the center
portions of said first and second S-shaped plates.
26. The method of claim 25 further comprising securing and
preventing pivoting of first and second S-shaped plates after said
engaging of said first and second S-shaped plates' surfaces to said
lateral surfaces of said first and second spinous processes,
respectively.
27. The method of claim 25 wherein said engaging comprises engaging
protrusions formed in said first and second surfaces of said first
and second S-shaped plates, to said lateral surfaces of said first
and second spinous processes, respectively.
28. The method of claim 27 wherein said protrusions are selected
from a group consisting of teeth, spikes, serrations, rough
coatings and ridges.
29. The method of claim 25 further comprising providing a post
member configured to pass through concentrically aligned
through-bore openings formed in said centers of said first and
second S-shaped plates.
30. The method of claim 29 wherein said second S-shaped plate
comprises top and bottom components configured to pivot around said
axis independent of each other.
31. The method of claim 30 wherein said top and bottom components
are configured to pivot around said post member and to set first
and second pivot angles with said first S-shaped plate,
respectively, thereby defining first and second spaces between said
first S-shaped plate and said top and bottom components,
respectively.
32. The method of claim 29 wherein said second S-shaped plate is
configured to pivot around said post member and to set first and
second pivot angles with said first S-shaped plate, respectively,
thereby defining first and second spaces between said first
S-shaped plate and said top and bottom portions, respectively.
33. The method of claim 29 wherein said post member comprises a
locking element for securing and preventing pivoting of said first
and second S-shaped plate.
34. The method of claim 33 wherein said post member comprises an
elongated bolt and said locking element comprises threads formed at
a portion of said bolt, dimensioned to engage inner threads in said
first S-shaped plate through-bore.
35. The method of claim 33 wherein said post member comprises an
elongated bolt and said locking element comprises threads formed at
a portion of said bolt, dimensioned to engage a nut after the bolt
exits said S-shaped plates through-bores.
36. The method of claim 25, wherein said center portions of said
first and second S-shaped plates are dimensioned to fit between
said first and second spinous processes and comprise edges sculpted
to conform to the shape of said spinous processes.
37. The method of claim 31, wherein said first and second pivot
angles comprise values between zero and 180 degrees.
38. The method of claim 25 wherein said first and second S-shaped
plates are pivoted to a horizontal orientation for sidewise
insertion of said method between said first and second spinous
processes.
39. The method of claim 25 wherein said first and second S-shaped
plates are assembled prior to being implanted between said first
and second spinous processes.
40. The method of claim 25 wherein said first and second S-shaped
plates are assembled after being implanted between said first and
second spinous processes.
41. The method of claim 25 further comprising providing a top
locking member configured to lock said first and second S-shaped
plates' top ends.
42. The method of claim 41 wherein said top locking member
comprises a long bolt configured to be threaded through bolt holes
formed through said first S-shaped plate's top end, said first
spinous process and said second S-shaped plate's top end.
43. The method of claim 41 wherein said top locking member is
selected from a group consisting of staples, cables, sutures, pins
and screws.
44. The method of claim 25 further comprising providing a bottom
locking member configured to lock said first and second S-shaped
plates' bottom ends.
45. The method of claim 44 wherein said bottom locking member
comprises a long bolt configured to be threaded through bolt holes
formed through said first S-shaped plate's bottom end, said second
spinous process and said second S-shaped plate's bottom end.
46. The method of claim 46 wherein said bottom locking member is
selected from a group consisting of staples, cables, sutures, pins
and screws.
47. The method of claim 25 wherein said first and second S-shaped
plates comprise material selected from a group consisting of
stainless steel, titanium, gold, silver, alloys thereof, absorbable
material, non-metal materials including synthetic ligament
material, polyethylene, extensible materials and combinations
thereof.
48. The method of claim 25 further comprising providing a center
plate configured to pivot around said axis and being dimensioned to
fit between said first and second spinous processes and comprising
edges sculpted to conform to the shape of said spinous
processes.
49. The method of claim 25 wherein said first and second S-plates
comprise adjustable lengths.
Description
CROSS REFERENCE TO RELATED CO-PENDING APPLICATIONS
[0001] This application claims the benefit of U.S. provisional
application Ser. No. 60/750,520 filed Dec. 14, 2005 and entitled
"SPINOUS PROCESS FIXATION IMPLANT`, the contents of which are
expressly incorporated herein by reference.
[0002] This application is also a continuation of U.S. application
Ser. No. 11/609,418 filed on Dec. 12, 2006 and entitled SPINOUS
PROCESS FIXATION IMPLANT the contents of which are expressly
incorporated herein by reference.
FIELD OF THE INVENTION
[0003] The present invention relates to a system and a method for
spinal stabilization through an implant, and more particularly to
spinal stabilization through attachment of the implant to the
spinous processes along one or more vertebras.
BACKGROUND OF THE INVENTION
[0004] The human spine comprises individual vertebras 30 (segments)
that are connected to each other to form a spinal column 29, shown
in FIG. 1. Referring to FIGS. 1B and 1C, each vertebra 30 has a
cylindrical bony body (vertebral body) 32, three winglike
projections (two transverse processes 33, 35 and one spinous
process 34), left and right facet joints 46, lamina 47, left and
right pedicles 48 and a bony arch (neural arch) 36. The bodies of
the vertebrae 32 are stacked one on top of the other and form the
strong but flexible spinal column. The neural arches 36 are
positioned so that the space they enclose forms a tube, i.e., the
spinal canal 37. The spinal canal 37 houses and protects the spinal
cord and other neural elements. A fluid filled protective membrane,
the dura 38, covers the contents of the spinal canal. The spinal
column is flexible enough to allow the body to twist and bend, but
sturdy enough to support and protect the spinal cord and the other
neural elements. The vertebras 30 are separated and cushioned by
thin pads of tough, resilient fiber known as inter-vertebral discs
40. Disorders of the spine occur when one or more of the individual
vertebras 30 and/or the inter-vertebral discs 40 become abnormal
either as a result of disease or injury. In these pathologic
circumstances, fusion of adjacent vertebral segments may be tried
to restore the function of the spine to normal, achieve stability,
protect the neural structures, or to relief the patient of
discomfort.
[0005] Several spinal fixation systems exist for stabilizing the
spine so that bony fusion is achieved. The majority of these
fixation systems utilize rods that attach to screws threaded into
the vertebral bodies or the pedicles 48, shown in FIG. 3C. In some
cases plate fixation systems are also used to fuse two adjacent
vertebral segments. This construction usually consists of two
longitudinal plates that are each placed laterally to connect two
adjacent pedicles of the segments to be fused. This system can be
extended along the sides of the spine by connecting two adjacent
pedicles at a time similar to the concept of a bicycle chain.
Current plate fixation systems are basically designed to function
in place of rods with the advantage of allowing intersegmental
fixation without the need to contour a long rod across multiple
segments. Both the plating systems and the rod systems add bulk
along the lateral aspect of the spine limits access to the pars and
transverse processes for decortication and placement of bone graft.
In order to avoid this limitation many surgeons decorticate before
placing the rods, thereby increasing the amount of blood loss and
making it more difficult to maintain a clear operative field.
Placing rods or plates lateral to the spine leaves the center of
the spinal canal that contains the dura, spinal cords and nerves
completely exposed. In situations where problems develop at the
junction above or below the fused segments necessitating additional
fusion, the rod fixation system is difficult to extend to higher or
lower levels that need to be fused. Although there are connectors
and techniques to lengthen the fixation, they tend to be difficult
to use and time consuming.
[0006] Accordingly, there is a need for a spinal stabilization
device that does not add bulk to the lateral aspect of the spine
and does not limit access to the pars and transverse processes for
decortication and placement of bone graft.
SUMMARY OF THE INVENTION
[0007] In general, in one aspect, the invention features an
implantable assembly for stabilization of spinous processes
including a first S-shaped plate having a first surface configured
to engage a first lateral surface of a first spinous process and a
second surface configured to engage a second lateral surface of a
second spinous process and a second S-shaped plate having a first
surface configured to engage a second lateral surface of the first
spinous process and a second surface configured to engage a first
lateral surface of the second spinous process. The first and second
S-shaped plates are configured to pivot around an axis
perpendicular to the center portions of the first and second
S-shaped plates.
[0008] Implementations of this aspect of the invention may include
one or more of the following features. The assembly may further
include a post member configured to pass through concentrically
aligned through-bore openings formed in the centers of the first
and second S-shaped plates. The second S-shaped plate is configured
to pivot around the post member and to set first and second pivot
angles with the first S-shaped plate, respectively, thereby
defining first and second spaces between the first S-shaped plate
and the top and bottom portions, respectively. The second S-shaped
plate may include top and bottom components configured to pivot
around the axis independent of each other. The top and bottom
components are configured to pivot around the post member and to
set first and second pivot angles with the first S-shaped plate,
respectively, thereby defining first and second spaces between the
first S-shaped plate and the top and bottom components,
respectively. The post member may include a locking element for
securing and preventing pivoting of the first and second S-shaped
plates. The post member may be an elongated bolt and the locking
element may be threads formed at a portion of the bolt, dimensioned
to engage inner threads in the first S-shaped plate through-bore,
or a nut after the bolt exits the S-shaped plate through-bore. The
first and second surfaces of the first and second S-shaped plates
may include protrusions configured to engage and frictionally lock
the S-shaped plates onto the first and second spinous processes.
The protrusions may be teeth, spikes, serrations, rough coatings or
ridges. The center portions of the first and second S-shaped plates
are dimensioned to fit between the first and second spinous
processes and comprise edges sculpted to conform to the shape of
the spinous processes. The first and second pivot angles may have
values between zero and 180 degrees. The first and second S-shaped
plates are pivoted to a horizontal orientation for sidewise
insertion of the assembly between the first and second spinous
processes. The assembly may be assembled prior to or after being
implanted between the first and second spinous processes. The
assembly may further include a top locking member configured to
lock the first and second S-shaped plates' top ends. The top
locking member may be a long bolt configured to be threaded through
bolt holes formed through the first S-shaped plate's top end, the
first spinous process and the second S-shaped plate's top end. The
top locking member may be staples, cables, sutures, pins or screws.
The assembly may further include a bottom locking member configured
to lock the first and second S-shaped plates' bottom ends. The
bottom locking member may be a long bolt configured to be threaded
through bolt holes formed through the first S-shaped plate's bottom
end, the second spinous process and the second S-shaped plate's
bottom end. The bottom locking member may be staples, cables,
sutures, pins and screws. The first and second S-shaped plates may
be made of stainless steel, titanium, gold, silver, alloys thereof,
absorbable material, non-metal materials including synthetic
ligament material, polyethylene, extensible materials or
combinations thereof. The assembly may further include a center
plate configured to pivot around the axis and being dimensioned to
fit between the first and second spinous processes and comprising
edges sculpted to conform to the shape of the spinous processes.
The first and second S-plates may have adjustable lengths.
[0009] In general, in another aspect, the invention features a
method for stabilizing spinous processes of a spinal column,
including providing a first S-shaped plate and engaging a first
surface of the first S-shaped plate with a first lateral surface of
a first spinous process and a second surface of the first S-shaped
plate with a second lateral surface of a second spinous process and
providing a second S-shaped plate and engaging a first surface of
the second S-shaped plate with a second lateral surface of the
first spinous process and a second surface of the second S-shaped
plate with a first lateral surface of the second spinous process.
The first and second S-shaped plates are configured to pivot around
an axis perpendicular to the center portions of the first and
second S-shaped plates.
[0010] Among the advantages of this invention may be one or more of
the following. The assembly stabilizes vertebras by attaching
plates to the spinous processes of the vertebras. This
stabilization device does not add bulk to the lateral aspect of the
spine and does not limit access to the pars and transverse
processes for decortication and placement of bone graft.
[0011] The details of one or more embodiments of the invention are
set forth in the accompanying drawings and description below. Other
features, objects and advantages of the invention will be apparent
from the following description of the preferred embodiments, the
drawings and from the claims
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Referring to the figures, wherein like numerals represent
like parts throughout the several views:
[0013] FIG. 1A is a side view of the human spinal column;
[0014] FIG. 1B is an enlarged view of area A of FIG. 1A;
[0015] FIG. 1C is an axial cross-sectional view of a lumbar
vertebra;
[0016] FIG. 2 is a posterior view of a portion of the spine with a
first embodiment of a spinous process fixation implant according to
the present invention affixed thereto;
[0017] FIG. 3 is a top view of the spine with the spinous process
fixation implant of FIG. 2 affixed thereto;
[0018] FIG. 4 is a front side view of the spinous process fixation
implant of FIG. 2;
[0019] FIG. 5 is a back side view of the spinous process fixation
implant of FIG. 2;
[0020] FIG. 6 is a right side perspective view of the spinous
process fixation implant of FIG. 2;
[0021] FIG. 7 is partially exploded right side perspective view of
the spinous process implant of FIG. 2;
[0022] FIG. 8 is a left side perspective view of the spinous
process fixation implant of FIG. 2;
[0023] FIG. 9 is a top perspective view of the spinous process
fixation implant of FIG. 2;
[0024] FIG. 10 is an exploded right side perspective view of the
spinous process fixation implant of FIG. 2;
[0025] FIG. 11 is a front side view of the elongated component 110
of FIG. 2;
[0026] FIG. 12 is a back side view of the elongated component of
FIG. 2;
[0027] FIG. 13 is a front side view of the top pivoting component
of FIG. 2;
[0028] FIG. 14 is a front side view of the bottom pivoting
component of FIG. 2;
[0029] FIG. 15 is a front side view of a second embodiment of a
spinous process fixation implant according to the present
invention, depicting the top and bottom pivoting components in the
closed position;
[0030] FIG. 16 is a front side view of the spinous process fixation
implant of FIG. 15 with the top and bottom pivoting components in
the open position;
[0031] FIG. 17 is a left side perspective view of the spinous
process fixation implant of FIG. 15, depicting the top and bottom
pivoting components in the closed position;
[0032] FIG. 18 is a left side perspective view of the spinous
process fixation implant of FIG. 15, depicting the top and bottom
pivoting components in the open position;
[0033] FIG. 19 is an exploded left side view of the spinous process
fixation implant of FIG. 15;
[0034] FIG. 20A is a right side view of the elongated plate
component 210 of FIG. 15;
[0035] FIG. 20B is a right side view of the top pivoting component
220 of FIG. 15;
[0036] FIG. 20C is a right side view of the bottom pivoting
component 230 of FIG. 15;
[0037] FIG. 21 is a front side view of a third embodiment of a
spinous process fixation implant according to the present
invention, depicting front and back pivoting components in the
closed position around the spinous processes;
[0038] FIG. 22A depicts insertion of the spinous process fixation
implant of FIG. 21 from the side with front and back pivoting
components in the open position;
[0039] FIG. 22B depicts pivoting the front and back pivoting
components of FIG. 21 to close them around the spinous
processes;
[0040] FIG. 23 is a front side view of the embodiment of a spinous
process fixation implant according of FIG. 21, depicting front and
back pivoting components in the closed position and locked position
around the spinous processes;
[0041] FIG. 24 is a front side view of a fourth embodiment of a
spinous process fixation implant according to the present
invention, depicting front top, front bottom and back pivoting
components in the closed position around the spinous processes;
[0042] FIG. 25A is a front side view of the front top pivoting
component of the spinous process fixation implant of FIG. 24;
[0043] FIG. 25B is a front side view of the front bottom pivoting
component of the spinous process fixation implant of FIG. 24;
[0044] FIG. 25C is a front side view of the back pivoting component
of the spinous process fixation implant of FIG. 24;
[0045] FIG. 26 is a front side view of the locking component of the
spinous process fixation implant of FIG. 24;
[0046] FIG. 27 is a front side view of a fifth embodiment of a
spinous process fixation implant according to the present
invention, depicting front and back pivoting components in the
closed and locked position around the spinous processes;
[0047] FIG. 28 depicts cutting and opening paths A and B around
superior and inferior adjacent spinous processes;
[0048] FIG. 29 depicts inserting back pivoting component of the
spinous process fixation implant of FIG. 27 along path A of FIG.
28; and
[0049] FIG. 30 depicts inserting front pivoting component of the
spinous process fixation implant of FIG. 27 along path B of FIG.
28; and
[0050] FIG. 31 is a front side view of a sixth embodiment of a
spinous process fixation implant according to the present
invention, depicting a single K-component body.
DETAILED DESCRIPTION OF THE INVENTION
[0051] The present invention relates to a system and a method for a
spinous process fixation implant.
[0052] Referring to FIG. 2, FIG. 3, and FIG. 4, a spinous process
fixation assembly 100 stabilizes two adjacent vertebras 92, 94 of
the human spine by engaging and locking their spinous processes 90a
and 90b, respectively. Spinous process fixation assembly 100
includes an elongate plate 110 and top and a bottom pivoting plates
120, 130, located opposite to plate 110 and configured to form a
K-shaped structure together with plate 110. Top and bottom pivoting
plates 120, 130 pivot around axis 140 (shown in FIG. 6) independent
from each other, forming angles 162, 164 with plate 110,
respectively. The pivoting motion of plates 120, 130 along
directions 144a, 144b and 146a, 146b, moves them close to or away
from the elongated plate 110, as shown in FIG. 4. Elongated plate
110 has a body 112 and front and back cross plates 114, 116,
extending at right angle to the front of the body 112 and back of
the body 112, respectively, as shown in FIG. 10, FIG. 11 and FIG.
12. Body 112 has a top end 113a, a bottom end 113b, an outer
surface 118 and an inner surface 117. Axis 140 passes through
apertures 152 and 154 formed in the centers of the cross plates
114, 116, respectively, as shown in FIG. 11 and FIG. 12. Cross
plates 114, 116 extend between the bottom surface and top surface
of the adjacent spinous processes 90a, 90b, respectively and have
edges 115 which are rounded and sculpted to correspond to the
geometry of the spinous processes 90a, 90b and lamina around which
they will fit once implanted. Cross plates 114, 116 are
substantially flat, parallel to each other and a gap is formed
between them sized to hold portions of the top and bottom pivoting
plates 120, 130, as shown in FIG. 7.
[0053] Referring to FIG. 10, FIG. 13 and FIG. 14, top pivoting
plate 120 has a main body 122 with top and bottom ends 123a, 123b,
respectively and inner 127 and outer surface 128, respectively. An
arm 124 extends downward from the bottom end 123b of the body 122
and a side plate 128 extends at right angle to the back of the body
122. The arm 124 has an aperture 126 located at the bottom left
corner and extends from the front side to the back side of the arm
124. Similarly, bottom pivoting plate 130 has a main body 132 with
top and bottom ends 133a, 133b, respectively, and inner and outer
surfaces 137, 138 respectively. An arm 134 extends upward form the
top end 133a and has an aperture 136 at the top left corner,
extending from the front side to the back side of the arm 134, as
shown in FIG. 10, and FIG. 14. A side plate 138 extends at right
angle from to the back of the body 132. All edges of plates 110,
120, 130 are rounded to prevent damage of the adjacent tissue
during implantation or spinal movement. Plates 110, 120, 130 are
made of stainless steel, titanium, gold, silver, alloys thereof,
absorbable material, non-metal materials including synthetic
ligament material, polyethylene, extensible materials or
combinations thereof. Plates 110, 120, 130 may have adjustable
lengths. In one example plates 110, 120, 130 have lengths of 30 mm,
15 mm, 15 mm, respectively, and the assembly may have a width
between 3 mm to 10 mm.
[0054] Referring to FIG. 7, a long bolt 180 passes through
apertures 152 and 154 of the cross plates 114, 116 of the elongated
plate 110 and though apertures 126 and 136 formed in the top and
bottom pivoting plates 120, 130, respectively. Bolt 180 has a head
181, a shaft 183 and threads 184 formed on the end portion of the
shaft 183. Threads 184 engage threads in the aperture 154 of the
back cross plate 116, in order to hold and secure the three
components 110,120, 130, of the assembly 100 together. In other
embodiments, a nut (not shown) is attached at the end of the bolt
180 to hold and secure the three components 110,120, 130, of the
assembly 100 together. In other embodiments bolt 180 is threaded
into the cartilage between the two vertebras to secure the three
components 110, 120, 130 together and to attach the assembly 100
onto the spine. The inner surfaces 117, 127, 137 of plates 110,
120, 130, respectively, have protrusions 111 that grab and
frictionally engage the sides of the spinous processes 90a, 90b, as
shown in FIG. 3, FIG. 11, FIG. 13 and FIG. 14. Protrusions 111 may
be teeth, serrations, ridges, and other forms of rough surfaces or
coatings that produce rough surfaces. The position of pivoting
plates 120, 130 relative to each other and relative to plate 110 is
locked with a set screw 182 passing trough the aperture 156 formed
in the upper right corner of the front cross plate 114. Tightening
of the set screw 182 locks the front and back cross plates 114, 116
to the pivoting plates 120 and 130. Engaging and locking the
spinous process fixation assembly 100 onto spinous processes 90a,
90b, prevents the components 110, 120 and 130 from moving sidewise
or up and down toward or away from each other during spinal
movement.
[0055] The assembled spinous process fixation assembly 100 is
implanted into the patient with the use of instrumentation (not
shown) between the two adjacent spinous processes 90a, 90b, as
shown in FIG. 2. The cross plates 114, 116 are placed between the
spinous processes 90a, 90b so that the body 112 of the elongated
plate 110 and the top and bottom pivoting plates 120, 130 fall on
the lateral sides of the spinous processes 90a, 90b. One spinous
process 90a lies between the top portion of the body 112 and the
top pivoting plate 120, as shown in FIG. 3, and the other spinous
process 90b lies between the bottom portion of the body 112 and the
bottom pivoting plate 130, with their inner surfaces 117, 127, 137
facing the lateral surfaces of the spinous processes 90a, 90b. On
each of the inner surfaces 117, 127, 137 of the plates 110, 120,
130, respectively, the protrusions 111 face toward the lateral
surface of the adjacent spinous process. At this point, the top and
bottom pivoting plates 120, 130 are pivoted as necessary to provide
the desired fit of the plates to the spinous processes. The bolt
180 is tightened, clamping the protrusions 111 into the surfaces of
the spinous processes and locking the three plates relative to each
other by engaging the threads of the aperture 154. The protrusions
111 and the threading of the bolt into aperture 154 of the back
cross plate 116 frictionally secures the spinous process fixation
assembly 100 onto the spinous processes 90a, 90b and helps prevent
the device from shifting or slipping.
[0056] Referring to FIG. 15, FIG. 16, FIG. 17, FIG. 18, in a second
embodiment of the spinous process fixation assembly 200, the top
and bottom pivoting plates 220, 230 are designed to pivot past each
other and to form any angle with the elongated plate 210 between 0
and 180 degrees. In particular, plates 220 and 230 pivot to a 90
degree angle relative to plate 210 and form a sidewise oriented T,
shown in FIG. 16 and FIG. 180. The assembly 200 of FIG. 16, with
the pivoting plates 220, 230 at a 90 degree angle with the plate
110, is inserted sidewise between the top and bottom spinous
processes 90a, 90b. Once the assembly is inserted, the plates 220
and 230 are pivoted upward and downward, respectively, and are
placed at angles relative to the plate 210 necessary to provide the
desired fit of the plates to the spinous processes. Sidewise
implantation of the assembly 200 has the advantage of reduced
trauma in the area between the spinous processes.
[0057] In this embodiment the top pivoting plate 220 has a main
body 222 with top and bottom ends 223a, 223b, respectively and
inner 227 and outer surface 228, respectively, shown in FIG. 19,
FIG. 20. Main body 222 has a width 229 dimensioned to allow plate
220 to pivot past plate 230 when placed in the gap 219 between the
two cross plates 214, 216 of plate 210. An arm 224 extends downward
from the bottom end 223b of the body 222. The arm 224 has an
aperture 226 located at the center of the bottom end of the arm and
extends from the front side to the back side of the arm 224. A
protruding annulus 225 surrounds aperture 226 and projects outward
form the back side of the arm 224. Annulus 225 is dimensioned to
fit within aperture 254 of the back cross plate 216. Aperture 226
includes inner threads (not shown) extending from the front to the
back side of the arm 224. Similarly, bottom pivoting plate 230 has
a main body 232 with top and bottom ends 233a, 233b, respectively,
and inner and outer surfaces 237, 238 respectively. Main body 232
has a width 239 dimensioned to allow plate 230 to pivot past plate
220 when placed in the gap 219 between the two cross plates 214,
216 of plate 210. An arm 234 extends upward form the top end 233a
and has an aperture 236 located at the center of the top end of the
arm and extends from the front side to the back side of the arm
234, as shown in FIG. 19 and FIG. 20C.
[0058] Elongated plate 210, top pivoting plate 220 and bottom
pivoting plate 230 are assembled together, as shown in FIG. 18.
Annulus 225 is inserted in the aperture 254 of the back cross plate
216 and the apertures 252, 236, 226 of the front cross plate 214,
bottom pivoting plate 230 and top pivoting plate 220, respectively,
are aligned. A long bolt 280 is inserted through the aligned
apertures and threaded in the inner threads of the aperture 226.
The position of pivoting plates 220, 230 relative to each other and
relative to plate 210 is locked with a set screw 282 passing trough
the aperture 256 formed in the upper left corner of the front cross
plate 214. Tightening of the set screw 282 locks the front and back
cross plates 214, 216 to the pivoting plates 220 and 230. Once
assembly 200 is implanted into the patient between the two adjacent
spinous processes 90a, 90b, the assembly is secured and locked in
position, according to the process described above.
[0059] Referring to FIG. 21, in a third embodiment the spinous
process fixation assembly 300 includes a front S-shaped plate 310
and a mirror image back S-shaped plate 320 connected at their
centers via a bolt 380 forming an X-shaped structure. The front
S-shaped plate 310 pivots relative to a back S-shaped plate 320
around pivot point 340 and the spinous process 90a of the top
vertebra 92 is frictionally engaged between the upper arms of
S-plates 310 and 320, while the spinous process 90b of the bottom
vertebra 42 is frictionally engaged between the lower arms of
S-plates 310 and 320. A bolt 380 is threaded through apertures
formed in the centers of the front and back S-plates, as shown in
FIG. 21. The inner surfaces of the upper and lower arms of the
S-shaped plates are sculpted to fit the shape of the spinous
processes and have protrusions that frictionally engage the sides
of the spinous processes and together with the bolt 380 securely
lock the assembly 300 between the spinous processes 90a, 90b.
[0060] Assembly 300, with the S-shaped plates 310, 320 assembled
and oriented horizontally, as shown in FIG. 22A, is inserted
sidewise between the top and bottom spinous processes 90a, 90b.
Once the assembly is inserted, plates 310 and 320 are pivoted
upward and downward, respectively, as shown in FIG. 22B, and they
assume a vertical orientation so that their corresponding inner
surfaces surround spinous processes 90a, 90b. Sidewise implantation
of the assembly 300 has the advantage of reduced trauma in the area
between the spinous processes.
[0061] Long bolts 370 may be added to this embodiment to further
anchor the assembly 300 on the spinous processes. If they are
added, appropriately sized holes must be drilled laterally through
the spinous processes prior to placement of the device. Once the
device is in place as described above, one long bolt 370 is
threaded through a bolt hole on the top end of plate 310, through
the drilled hole in the spinous process 90a, then out through a
bolt hole on top end of plate 320. A second long bolt 370 may also
be threaded through a bolt hole on the bottom end of plate 310,
through the drilled hole in the spinous process 90b, then out
through a bolt hole on the bottom end of plate 320. Tightening of
bolts 380 and 370 securely locks the assembly 300 around spinous
processes 90a, 90b.
[0062] In another embodiment of the spinous process fixation
assembly 400, shown in FIG. 24, the front S-shaped plate include a
top pivoting component 410, shown in FIG. 25A, and a bottom
pivoting component 420, shown in FIG. 25B, forming the top and
bottom portions of the S-curve, respectively. The back S-plate 430
is formed as one component S-shaped plate with a curved top portion
432, a bottom curved portion 434 and a rounded center 438 having an
aperture formed in its center 436, shown in FIG. 25C. The top
pivoting component 410 includes an upward extending curved portion
412 and a lower rounded end 414 having an aperture 416 formed in
its center. The bottom pivoting component includes a downward
extending curved portion 422 and an upper rounded end 424 having an
aperture 426 formed in its center. The front and back surfaces of
the rounded end 424, the back surface of the rounded end 414 and
the front surface of the rounded center 438 have radial extending
grooves 425, shown in FIG. 25B and FIG. 25C. Grooves 425 define
one-degree arcs, thus allowing the plates 410, 420, 430 to rotate
relative to each other by one degree steps. Assembly 400 further
includes a block 440 dimensioned to fit between the adjacent
spinous processes 90a, 90b and having top and bottom edges
configured to correspond to the geometry of the spinous processes
90a, 90b and lamina around which they will fit once implanted.
Different sized blocks are used to accommodate different spacings
between adjacent spinous processes 90a, 90b. The front and back
surfaces of block 440 also include grooves 425 around an aperture
446 formed n the center of the block. The top pivoting plate 410,
bottom pivoting plate 420, block 440 and the back plate 430 are
arranged so that their corresponding apertures 416, 426, 446, 436
are aligned and a bolt 480 is threaded through these apertures.
Once the assembly 400 is inserted, the plates 410 and 420 are
pivoted upward and downward, respectively, and are placed so as to
surround the spinous processes. The inner surfaces of the upper and
lower arms of the S-shaped plates are sculpted to fit the shape of
the spinous processes and have protrusions that frictionally engage
the sides of the spinous processes and together with the bolt 480
securely lock the assembly 400 between the spinous processes 90a,
90b.
[0063] Long bolts 370 may be also added to this embodiment to
further anchor the assembly 400 on the spinous processes, as was
described above. Alternatively, a staple 450 may be placed on the
top and bottom open ends of the plates 410, 420 and 430, as shown
in FIG. 27. In other embodiments banding, cabling or suturing may
be used to attached the ends of plates 410, 420 and 430 to the
spinous processes. The outer surfaces of the plates 410, 420 and
430 may be rounded, as shown in FIG. 24 or straight, a shown in the
embodiment 500 of FIG. 27.
[0064] Referring to FIG. 28, FIG. 29 and FIG. 30, the process of
implanting the spinous process fixation assembly between two
adjacent vertebrae includes the following steps. First an incision
is made in the patient's back and paths A and B are opened along
bony planes 95 and through ligaments 96 between the adjacent
spinous processes 90a, 90b. Path B is mirror image of path A about
the centered sagittal plane 98. Next, the back component 510 of the
assembly of FIG. 27 is inserted along path A, as shown in FIG. 29,
and the ends 513a and 513b are attached to the spinous processes
90a, 90b, respectively. Next, the front component 520 is inserted
along path B and a bolt 580 is threaded through the apertures 512,
522 formed in the centers of back and front components 510, 520,
respectively. The front and back components are pivoted around the
axis passing through their central apertures 512, 522, so that
their ends 513a, 523a, 513b, 523b surround and close around the
spinous processes 90a, 90b. The ends 513a, 523a, and 513b, 523b are
then attached to spinous processes 90a, 90b, respectively as shown
in FIG. 30. The ends may be attached with any of the above
mentioned methods including frictional engagement of protrusions,
long bolts, staples, cabling, banding or suturing. Plates 510, 520
are dimensioned so when assembled, assembly 500 has a width 535
that covers and protects the spinal cord after laminectomy or
facectomy.
[0065] In a sixth embodiment, shown in FIG. 31, spinous process
fixation assembly 600 includes one K-shaped component having an
elongated plate 610 and two deformable plates 620, 630 extending
upward and downward, respectively, from the center 615 of the
elongated plate. A top gap 612 is formed between the top portion of
the elongated plate 610 and the upward extending plate 620. A
bottom gap 614 is formed between the bottom portion of the elongate
plate 610 and the downward extending plate 630. The K-shaped
assembly is placed between the adjacent spinous processes 90a, 90b,
as shown in FIG. 31, and a plate 640 is placed in the center of the
assembly 600 on top deformable plates 620, 630. A bolt 680 is
threaded through apertures formed in the center of plate 640 and
the center 615 of the K-shaped component, as shown in FIG. 31.
Tightening of the bolt 680 down applies pressure onto the plate
640, which is transferred to the top and bottom deformable plates
620, 630. Plates 620, 630 move closer to plate 610 and the widths
of the top and bottom gaps 612, 614 is reduced, resulting in
engaging protrusions 111 formed on the inner surfaces of plates
610, 620, 630 with the spinous processes 90a, 90b and tightening of
the plates 620, 630 and 610 around the spinous processes 90a, 90b.
The ends of the plates 620, 630 may be further attached to the
spinous processes with any of the above mentioned methods including
long bolts, staples, cabling, banding or suturing.
[0066] Other embodiments are within the scope of the following
claims. For example, vertebras 92 and 94 may be any two vertebras,
including lumbar L1-L5, thoracic T1-T12, cervical C1-C7 or the
sacrum. The fixation assembly 100 may extend along multiple
vertebras. The K shaped structure may be also configured as a
mirror image of the structure in FIG. 2, with the pivoting plates
120, 130 located on the left side and the elongated plate 110
located on the right side of the FIG. 2. The elongated plates 110,
220 and the top and bottom pivoting plates 120, 220, and 130, 230
of the embodiments of FIG. 4 and FIG. 15, respectively, may have
adjustable lengths. Similarly, S-plates 310, 320 of the embodiment
of FIG. 21 and plates 410, 420, 430 of the embodiment of FIG. 24
may have adjustable lengths. Similarly, elongated plate 610 and
deformable plates 620, 630 of the embodiment of FIG. 31 may have
adjustable lengths. The main bodies 122, 132 of pivoting plates
120, 130 may be detached from the corresponding extending arms 124,
134. Bodies 122, 132 may be attached to the extending arms 124, 134
via hinges (not shown) which allow them to swing open and close for
better placement around the corresponding spinous processes 90a,
90b.
[0067] Several embodiments of the present invention have been
described. Nevertheless, it will be understood that various
modifications may be made without departing from the spirit and
scope of the invention. Accordingly, other embodiments are within
the scope of the following claims.
* * * * *